1. Field of the Description
The present invention relates, in general, to display of 3D imagery without use of glasses or special headgear, and, more particularly, to a method of generating multiple views from a stereo view or image stream (e.g., one used for displaying 3D images with polarized or shuttered glasses) to allow 3D viewing without the need for glasses or special headgear. The present invention may be thought of as relating to the automated conversion of digital files of stereo views into digital files of multiple views and to the operation of 3D displays to display 3D imagery to viewers. The conversion is “automated” through the use of software or a software program(s) running on a computer (e.g., a microchip conversion system), and the produced multiple views are, in some embodiments, adapted for display on a monitor or television (e.g., a liquid crystal display (LCD), plasma display, or other display/monitor device) that includes a barrier grid or lenticular lens sheet/layer (e.g., a monitor adapted for 3D viewing).
2. Relevant Background
Displays that provide the illusion of three dimensions have experienced a rebirth in the past few years. For example, a number of 3D televisions are now available for use in homes and home theaters. These 3D televisions generally operate by displaying a stream of left and right eye images in an alternating or time-multiplexed manner (e.g., left-right-left-right). Switching occurs so quickly that the viewer does not sense a flicker or change in the display. The viewer wears special headgear or glasses that operate in a synchronized manner with the display to only allow the light associated with the left eye image to reach the viewer's left eye and with the right eye image to reach the viewer's right eye.
For example, the 3D glasses may be shutter glasses that rapidly switch between allowing light to reach the left or the right eye, with the shuttering operation controlled to be time-synchronized with the display (e.g., a liquid crystal display (LCD) television monitor or the like). In other cases, the television monitor or display is configured to output two different types of polarized light to present the left and right eye images. In this case, the viewer typically wears glasses with two different lenses that are polarized in a manner to allow the left eye to view light from the display polarized in one manner and the right eye to view light from the display polarized in a second manner. Such polarized 3D glasses have been in use in theaters for many years.
While most commercial displays rely on the use of special glasses, it is generally agreed by those in the 3D entertainment industry that displays able to provide a 3D viewing experience without glasses or headgear offer significant advantages. Presently, there are 3D display systems that can deliver left eye images to a viewer's left eye and right eye images to a viewer's right eye. However, these 3D display systems each have significant limitations. Some 3D display systems require the viewer to have their head in a specific position and to not move at all during the viewing experience as this may cause the wrong image to be viewed (e.g., the right eye to see the left eye image stream or vice versa) or to lose the image altogether. For example, 3D televisions or the like may have a “sweet spot” where the viewed imagery appears in 3D such as directly in front of the center of the screen, but the volumetric effect is ruined if that viewer moves their head to the left or right even a small amount (e.g., several inches). As a result, such 3D display devices are only useful for one or two viewers viewing at a particular location.
To support existing 3D technologies, the accepted origination media has typically been stereo views such as for the production of 3D effects in movies, video games, and other applications. Stereo views (left and right eye views or images of an object or scene) are generated as a standard in the entertainment industry such as during filming or during rendering for animated movies and games (e.g., two cameras associated with a viewer's left and right eyes are used). In some cases, the views are compiled as an anaglyph by polarizing light by color and creating separation between the left and right eye images. The viewer can observe the 3D image by wearing a corresponding pair of glasses with red and blue filters (passive) or an active shutter system that selectively flashes/passes the left or right eye images in an alternating manner. Alternatively, a barrier grid or lenticular lens sheet/array can be used on a display device (e.g., placed on the front of an LCD or plasma display) to show two views to the viewer, which requires the viewer be centered perfectly with regard to the display device to experience a quality 3D effect.
The general public assessment of 3D viewing in gaming, television, and other applications is somewhat negative because of the necessity of wearing glasses or headgear or because of the very small “sweet spot” for viewing with a glasses-free 3D display device. Studies have, in fact, indicated that the glasses themselves are the primary deterrent to the acceptance to 3D media and displays. Hence, the goal of many in the entertainment industry is to develop 3D display technologies that do not require glasses or special headgear to create effective 3D effects for viewers. Preferably, such 3D display technology would also address or overcome the “sweet spot” or fixed head location limitation that exists with many 3D display devices as viewers want the freedom to move their heads without ruining the 3D effect and purchasers of the displays want to be able to view the displays with larger groups (e.g., allow a family to view a display while sitting side-by-side on a couch or in a row of a home theater).